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SRON is one of the leading institutes in the development of the X-ray Integral Field Unit (X-IFU) for X-ray space telescope ATHENA, to be launched in 2028. X-IFU will be a 2-D imaging camera annex spectrograph that is cooled to sub-Kelvin level. The spectrograph will be able to produce a spectrum for each pixel of the captured image and derive the characteristics of gas as hot as 10 million degrees Kelvin.
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Crucial to this set-up are TES-detectors and their read-out. TES detectors are super sensitive in showing very slight temperature changes when photons are absorbed in the connected absorber. The change in temperature is a measure of the energy of the detected X-ray photon. The accurate energies of the X-ray light detected by Athena will give astronomers highly valued information about the quantity and type of gases that black holes blast into space, for example.
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SRON is now testing TES detector arrays, as well as their readout electronics system. The testing takes place in a cryostat that cools the detector array down to a temperature under 1 Kelvin. An X-ray source is then shone upon the array.